MAGNETOSTRICTIVE RESONATOR DETECTING DEVICE, VEHICLE, AND TRAFFIC SYSTEM

摘要

PROBLEM TO BE SOLVED: To detect the position of a vehicle while reducing the influence of others by installing an antenna in a specific direction corresponding to a magnetostrictive resonator buried or installed under or nearby a road. ;SOLUTION: The loop antenna 3 is installed under the vehicle body so that its loop face is in almost parallel to the road surface 2. The loop antenna 3 radiates the electromagnetic wave of the resonance frequency of the magnetostrictive resonator 1 as a fixed short-time addressing radio wave and receivers the electromagnetic wave that the magnetostrictive resonator 1 radiates at the mechanical resonance within a subsequent certain short time to detect the relative position of the loop antenna 3 to the magnetostrictive resonator 1. When the magnetostrictive resonator 1 is buried at almost right angle to the road surface 2, the maximum output is obtained by the loop antenna 3 at the time of positioning right above the magnetostrictive resonator 1 and when the loop face is set at almost right angle to the road surface, the minimum output is obtained at the time of positioning right above the magnetostrictive resonator. The influence of opposite traveling vehicles and parallel traveling vehicles is reduced by varying the angles of the magnetostrictive resonator and the loop antenna.;COPYRIGHT: (C)1999,JPO